From: Joe Van Dyk <joevandyk@...>
Date: 2005-08-03T10:39:13+09:00
Subject: Re: extconf.rb search path

On 8/1/05, Ara.T.Howard <Ara.T.Howard@noaa.gov> wrote:
> On Tue, 2 Aug 2005, Joe Van Dyk wrote:
> 
> > On 8/1/05, Ara.T.Howard <Ara.T.Howard@noaa.gov> wrote:
> >> On Tue, 2 Aug 2005, Joe Van Dyk wrote:
> >>
> >>> Hi,
> >>>
> >>> Whenever I run extconf.rb for gnome2, it compiles against the gnome
> >>> libraries found in /usr.  I want it to compile against the gnome
> >>> libraries found in /usr/local.  Isn't that what it should do by
> >>> default?
> >>>
> >>> Anyways, how can I get the gnome2 Ruby extensions to compile against
> >>> the headers/libraries in /usr/local?
> >>>
> >>> Thanks,
> >>> Joe
> >>
> >> try this
> >>
> >>    ~ > LD_LIBRARY_PATH=/usr/local:$LD_LIBRARY_PATH LD_RUN_PATH=/usr/local:$LD_RUN_PATH ruby extconf.rb
> >>
> >> perhaps your compiler will like this...
> >>
> >> probably there is also a
> >>
> >>    --with-gnome-dir=/usr/local
> >>
> >> option for that extconf.
> >>
> >> -a
> >> --
> >
> > Weirdly, if I run /usr/local/bin/ruby (and not /usr/bin/ruby) on
> > extconf.rb, it uses libraries/headers in /usr/local (and not /usr).
> >
> > So, part of it seems to depend on where Ruby is installed.
> 
> 
> absolutely - you should always be aware of which ruby you are using to compile
> extensions.  basically ruby caches tons of stuff when it's compiled itself.
> it stores all this info and this is the foundation of 'mkmf', which extconf.rb
> uses.  this should be illuminating:
> 
>     ruby -r rbconfig -r yaml -e 'y Config::CONFIG'
> 
> if you're using the 'right' ruby you should see a /usr/local or two in there.
> 
> another rule of thumb: unless you understand why you wouldn't do so - always
> set LD_RUN_PATH to your system libdir (for example /usr/local/lib) when
> compiling extensions.  this is __very__ important in the case of ruby libs
> which themselves require libs : for example sqlite or gnome.  if you don't set
> this you'll have issues at runtime with the gnome-ruby libs loading gnome libs
> from /usr/lib/ vs. /usr/local/lib.  run ldd on the ruby-gnome extension to see
> what i mean.  if you re-compile with LD_RUN_PATH set to /usr/local you'll see
> a difference.
> 
> btw my command above should have been
> 
>    ~ > LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH LD_RUN_PATH=/usr/local/lib:$LD_RUN_PATH ruby extconf.rb


I have new libraries installed in /opt/lib.  LD_LIBRARY_PATH and
LD_RUN_PATH include /opt/lib.  When I run extconf.rb, it generates
Makefiles that don't include -L/opt/lib.  And running ldd on the
resulting shared library shows no libraries from /opt/lib.

Ideas?
Joe